Porcas Quadradas: Normal - Leve - Regular
REFERÊNCIA ASME / ANSI B18.2.2 - 1987 (Tabela 1)
| Diâmetro | F | G | H | |||
| Nominal | máx. | min. | máx. | min. | máx. | min. |
| 1/4" | 11,125 | 10,795 | 15,722 | 14,833 | 5,969 | 5,156 |
| 5/16" | 14,274 | 13,893 | 20,193 | 19,075 | 7,188 | 6,324 |
| 3/8" | 15,875 | 15,392 | 22,453 | 21,132 | 8,788 | 7,874 |
| 7/16" | 19,050 | 18,491 | 26,949 | 25,400 | 10,007 | 9,042 |
| 1/2" | 20,624 | 20,015 | 29,184 | 27,482 | 11,633 | 10,617 |
| 5/8" | 25,400 | 24,612 | 35,915 | 33,782 | 14,452 | 13,335 |
| 3/4" | 28,575 | 27,635 | 40,411 | 37,947 | 17,272 | 16,052 |
| 7/8" | 33,324 | 32,232 | 47,142 | 44,246 | 20,116 | 18,796 |
| 1" | 38,100 | 36,830 | 53,873 | 50,571 | 22,936 | 21,513 |
| 1.1/8" | 42,875 | 41,427 | 60,604 | 56,870 | 26,162 | 24,638 |
| 1.1/4" | 47,625 | 46,024 | 67,360 | 63,220 | 28,600 | 26,974 |
| 1.3/8" | 52,374 | 50,647 | 74,091 | 69,545 | 31,419 | 29,692 |
| 1.1/2" | 57,150 | 55,245 | 80,822 | 75,844 | 34,239 | 32,410 |